Process of making piston rings



Oct. 9, 1928.

W. J. SlX

PROCESS OF MAKING PISTON RINGS Filed Sept. 28, 1926 I N V EN TOR. WHL 75/? J J/x.

A TTORNEYS.

I ring from straight strips ofstock by rolling coil along the groove "16 whereby the coil Patented pctifi, 1928. I 1,686,937

(UNITED STATES PATENT-OFFICE.

wanna J. as, or mnmnnroms, mmmm, ASSIGNOR, BY manor AND MnsNEwAsi srenmmrrs, To B. n. EMANUEL, rausrnn; v

' rnocnss OF MAKING rIs'roN muss. ap ication flled septeniber 28, 1926. Seria1 No.138,242. This invention pertains to a process of :of a'n oval shape in cross section so as to mak ng split IlIigS by forming the metal permit the C0115 to be clamped in position rather than casting the same. at an angle thereto as illustrated in Fig.

The object of the process is to form a split A cuttingtool is then. passed through the "the stock toflproper dimensionsdn cross secis cut into a plurality of-split rings 17. By

tion and Ithen coiling it into cylindrical reason ofthe angular position of the coil the spring-like formation of substantially the rings are thus split on an angle inthe usual desired diameter, after which the coiled ma-' manner.

l0 terial is cut at the proper angle so'as to Upon the rings beirig removed from the as "split the same ina plurality of split rings. arbor 15 they are placed upon thearbor I The principal feature'of the invention 18 which is cylindrical in its general form resides in thesizing and forming of the but which has a relievedside, extending lonring into a true'circle with the proper gap gitudinally thereof throughout substantially v between: the split ,ends,- in such a manner athird of its peripheral surface as illustrated in y that'the ring will'retain its form against in Fig. 5 bythe dottedlines A-,B and as distortion, and its split ends will lie normally shown in Fig. 6 wherein the true circle bein the are" of'the circle formed by the ring. tween. the lines AB is showndotted. In'-- Thefull nature of the invention will be termediate of the relieved surface the arbor '1 understood""-from the accompanying draw-' is marked by an indicating line C for the conings and the following description and venience of the workman. The said'arbor is claims. I I l of the'properdiameter for the rings to be Fig. 1 is a diagrammatic illustration of made, which is slightly greater than the dithe' means for coiling the strip. Fig. 2 is a amete'r of the split ring before mounting the 725 perspective viewof thecoiled strip. Fig.3 same thereon. This causes the ring to be so is a diagrammaticillustration of the means spread so'astoslightly increase the gap bef forcutting the coil into a plurality of split tween the free ends thereof, and also causes Gil rings; Fig. 4; is a'pe'rspectlve view of a split said. free ends tobe drawn inwardly to conv ring. Fig. 5 is'a front elevation of a shapform to the relieved surface AB. 7 ing arbor. Fig. 6 is a section taken on the The arbor with the rings mounted thereon 5:, line 6'6 of Fig. 5. v is then placed in a heat treating furnace so 7 The process consists in'takin a strip of that the second heat treating action causes metal 10 substantially rectan al in cross the rings to maintain their size, shape, an section, the metal bein of stee iron, bronze wall tension. 7 or aiiy suitable material, passing the metal The. ring v thus formed of the proper dithrough the sizin rollers 11, compressing ameter and propergapbetwe en the free it to the desired imensions and forcing it ends are thereupon finished by grinding and against a fixed forming roller 12 having a polishing the surfaces thereof, which action curved surface .13 which will'cause the metal causes a certain stress and strain to be set p strip to wind into a cylindr cal spring-like up in the middle, which has the action of formation 14 as shown in Flg- 2- causing the free split ends to be forced outj The cylindrical coil is formed Wl a wardly from their relieved position to that slightly ess diameter than the rings to be f the true circle, whereby the completed made h r f m, and then-Stretched 9? 3 ring remains in the form of a true circle cylindrical fl 1 a g o e throughout its entire circumference. diameter than the 1ns1 e diameter of 9 This process as above described has the when rolled, less than the lnslde efieot of overcoming the hereto-0 53 diameter of t finishe g- The coil thus experienced wherein the ring formed in this I stretched over said arbor is then heat treated manna: normauy was t f round or t ill the wi so thftti/the W11 a true circle, the free ends protruding-out retain its shape and acqul a p g wardly from'the circle so that it was of sion so as to cause it to return to its proper r at diameter in a plane through the split dimensions upon being distorted. portion than at right angles thereto. This The heat treated coil is then removed from difficulty has been overcome by heat treating the arbor and placed upon a cutting arb the rings on a relieved arbor to such an ex- 111 other hand, a ring of 3.75 inches diameter should be heat treated on an. arbor having its surface A-B relieved substantially .060 of an inch.

The invention claimed is:

1. The process of forming split rings consisting in distorting said rings so thatthe adjacent free ends thereof will extend within a true circle passed thereabout, heat treating said rings in such deformed condition, and thereafter grinding or turning the same ,so as to vary the stress of the metal and cause said ends to resume their normal circular position. I

2. The process of forming split rings consisting of spirally winding a strip of metal into a helical coil, cutting the coil to form individual split rings deforming the abutting free ends of said rlngs out of round, heat treating the same in their deformed condition, and thereafter grinding or turning the same so as to vary the stress of the metal and cause them to return to their normal circular formation.

3. The process of forming split rings consisting of spirally winding a strip of metal into a cylindrical coil, cutting the coil to form individual rings, heat treating said rin s with the free abutting ends formed slightly 4 inwardly, and thereafter grinding or turning the surface of said rings so as to vary the stress of the metal whereby the ends thereof .Will be brought to conform to a true circle.

' 4. The process of forming split rings consisting of spirally winding a strip of metal into a helical coil, cutting the coil to form in "dividual rings, mounting the same on an arbor having a portion of its face relieved adjacent the split ends of the rings, heat treating the rings thereon, and thereafter grinding or turning the rings so as to vary the stress of the metal and bring them back to. normal circularfor-mation.

5. The process of forming split rings consisting of spirally Winding a strip of metal into a helical coil, heat treating the same, cutting the coilto form individual, rings, mounting said rings on an arbor of the diameter desired therefor, said arbor having that portion thereof adjacent the split ends of the rings relieved, and being ofsuliicient diamresets? eter to cause the free ends of said rings to be drawn inwardly against said relieved surface, heat treating said rings' thereon and thereafter grinding or turning said rings so as to vary the stress of the metal and cause the deformed ends thereof to return to true circular position.

6. The process of forming piston rings consisting' of spirally winding a strip of metal into a helical coil, mounting the same over a cylindrical arbor so as to stretch said coil'into true cylindrical form, mounting said coil over a supporting arbor and clamping the same in angular relation thereto, cutting said coil at an angle so as to form individual split rings, mounting said individual rings over an arbor of the desired diameter and having that portion thereof adjacent the split ends of the rings relieved, whereby said free ends may 'be drawn inwardlythereagainst, heat treating said rings on said arbor, and. thereafter grinding or turning said rings so as to vary the stress of the metal whereby their ends will resume a true circular formation.

7. The process of forming split rin s consisting of'spirally winding a strip of metal into a helical coil, heat treating the same,

cutting the coil to form individual rings,

rings so as to vary the stress of the metal and cause the deformed ends thereof to return to true circular position.

8. The process of forming sp lit rings consisting of mounting said rings on an arbor having a portion of its face relieved adjacent the split ends of the rings, said arbor being of slightly larger diameter than the normal diameter of said rings for spreading the same and drawing the free spread ends thereof inwardly 'a'djacent the relieved portionwhereby said ends will extend within a true circle, heat treating the rings on said arbor,

and thereafter grinding the rings so as to vary the stress of the metal and bring them back to normal circular formation.

In witness whereof, I have hereunto affixed my signature.

WALTER J. SIX. 

